None.
1. Field of the Invention
This invention relates to the field of marine sea chests, specifically to a sea chest configured for flush-mounting within the hull of a marine vessel having inboard engines to provide a large volume of sea water substantially without drag or cavitation for cooling the engines. The inlet through the bottom surface of the present invention sea chest has a critical keyhole shape that causes eddys to form at its outside edges when the marine hull into which it is mounted moves in a forwardly direction and further causes seawater to flow into the sea chest at the center of each leading edge. The present invention sea chest also has an orifice through its top surface from which a quick burst of air or water can be sent to clean debris clogs and eliminate the need for manual cleaning. Such debris removal can be performed on a voluntary basis, or as an automated response to a predetermined amount of change in monitored data, such as temperature readings. Size is not a limiting factor and the present invention sea chest can be made to any size appropriate to the vessel to which it is installed, as long as the shape of the keyhole inlet is preserved. Also, it can be mounted almost anywhere below the water line of a marine hull, but typically would be in a location near the inboard engines. Although not limited thereto, use of the present invention is generally contemplated for large and high-speed marine vessels. However the present invention sea chest can also provide benefit to other marine vessels, including those having a length dimension as small as twenty feet.
2. Description of the Related Art
One use for sea chests in the hulls of large marine vessels is to collect the seawater needed for engine cooling. Current sea chests typically have one large opening through a bottom surface for drawing in water and one or more inlet openings through an opposing top surface leading to seawater pumps. The effectiveness of a sea chest depends upon a combination of its size and the volume of seawater that can flow into it and made available to the seawater pumps for engine cooling. To keep the vegetation, garbage, and other debris often found in seawater from entering the sea chest and clogging the inlet openings of the seawater pumps, a screen or grill is generally employed )over the large opening of the sea chest. Divers are required periodically for manual cleaning of such screens and grills. In addition to the cleaning expense, many prior art sea chests seawater have scoops to collect seawater that produce a considerable drag. In contrast, the present invention provides a more efficient sea chest inlet configuration through its bottom surface that enhances seawater flow into the inlet openings leading to the seawater pumps. The present invention does not require a screen or grill covering, since it has a purge opening through its top surface that allows for a quick burst of air or water to unblock any type of debris that might be temporarily clogging it. It also has a flush mounting within the marine hull that prevents drag. Further, since no divers are required for periodic cleaning, operating costs for a marine vessel using the present invention are reduced. There is no sea chest known with a keyhole-shaped inlet opening through its bottom surface and all of the advantages of the present invention.
The primary object of this invention is to provide a sea chest that is configured and positioned to induce a large volume of seawater through the opening in its bottom surface. A further object of this invention is to provide a sea chest that draws sufficient volumes of seawater to eliminate cavitation. It is also an object of this invention to provide a sea chest that prevents drag. A further object of this invention is to provide a sea chest that is easily and cost-effectively maintained. It is also an object of this invention to provide a sea chest that can be mounted almost anywhere in a ship""s hull, although preferably near to the engines. A further object of this invention is to provide a sea chest with durable construction for long-term use. It is also an objective to provide a means of cooling marine engines in the event of water pump failure during a performance run.
As described herein, properly manufactured, and installed flush with the hull of a boat or large ship, the present invention sea chest provides a large volume of seawater for the cooling of marine engines with little or no drag. The flush mounting and resulting elimination of drag reduces fuel consumption. In addition, the small size and simple design of the present invention, as compared to prior art sea chests, allows it to be mounted almost anywhere in a marine hull, although typically it would be positioned near to the engine location. The large volume of seawater flowing through the present invention sea chest is provided by the unique keyhole shape of the single inlet opening through its bottom surface, which causes the laminar flow across a forwardly moving marine hull to form eddys at the outside edges of the keyhole opening and seawater to flow into the sea chest at the center of its leading edge. The eddys that are formed on the two angular sides of the keyhole-shaped inlet redirect the inertional energy to flow upward into the sea chest, inducing the main flow of seawater to follow. The eddys are formed by the rounded edges on the bottom side of the narrow portion of the keyhole-shaped opening. The efficiency of the sea chest can be increased by use of inwardly sloping edges adjacent to the narrow portion of keyhole-shaped inlet. The rear portion of the keyhole-shaped opening, with its larger and wider dimensions, is also preferably angled on its rear topside surface to enhance upward flow and maximize efficiency of the present invention sea chest. Thus, due to the velocity of the hull as it moves in a forwardly direction, the keyhole-shaped opening prevents water from bypassing it and as long as a bypass valve is added at the pump, the present invention sea chest will continue to provide seawater for engine cooling purposes even in the event of water pump failure during an endurance run. Due to the large amount of seawater induced to flow into the keyhole-shaped inlet, cavitation is eliminated as the seawater moves through the top surface of the sea chest and upward into the inlet side of the seawater pumps, preventing steam bubbles that are low in temperature and pressure from forming. The operating cost of a marine vessel using the present invention sea chest is also reduced since it is easily and cost-effectively maintained. Instead of requiring usage of a screen or grill, and divers to periodically clean vegetation, garbage, and/or other debris there from, a quick purging burst of air or water can be forced from the orifice through the top surface of the present invention sea chest to dislodge anything clogging it. The air and water bursts can be manually performed or automatically activated in response to a predetermined amount of change in monitored data. Also, the most preferred embodiment of the present invention sea chest is attached to a collar on the inside of the hull with a large number of closely spaced-apart oversized bolts, to keep it securely attached to the hull. The use of oversized bolts, and a large number of them, increases sea chest longevity. Recessed perimeter openings through the bottom surface of the sea chest are configured and dimensioned for flush mounting of the bolts.
While the description herein provides preferred embodiments of the present invention, it should not be used to limit its scope. For example, variations of the present invention, while not shown and described herein, can also be considered within the scope of the present invention, such as variations in the perimeter and depth dimensions of the sea chest; the thickness of the collar used on the inside of the marine hull for sea chest attachment; the number, size, and type of bolts used to attach the collar and sea chest in their usable positions against the marine hull; the type of sealant used between the collar, sea chest, and hull; the size of the purge orifice through the top surface of the sea chest; and the length and width dimensions of the single keyhole opening through the bottom surface of the sea chest although such dimensions must remain in proportion when elongated to substantially preserve the keyhole configuration for maximum efficiency during use. Thus, the scope of the present invention should be determined by the appended claims and their legal equivalents, rather than being limited to the examples given.